RecruitingNCT00272883
Neuromuscular
Congenital Fiber Type Disproportion
Also known as CFTD, congenital myopathy with fiber type disproportion
Congenital Fiber Type Disproportion is a congenital myopathy defined histopathologically by type 1 muscle fibres that are at least 25% smaller than type 2 fibres, in the absence of other specific pathological features. It is a genetically h
ORPHA:2020 ↗Gene ACTA1Gene RYR1Gene TPM3Prevalence Less than 1 in 100,000Onset Congenital or early infancyAutosomal dominant or recessive (gene-dependent)
1
studies recruiting now
as of 7 Sept 2026
2
studies registered in total
as of 7 Sept 2026
1
countries with a recruiting site
as of 7 Sept 2026
9 Jan 2006
most recent study posted
among recruiting studies
Recruiting trials
Showing the 1 most recently updated recruiting study, as recorded 7 Sept 2026. Live status on each study page.
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About Congenital Fiber Type Disproportion
Congenital Fiber Type Disproportion is a congenital myopathy defined histopathologically by type 1 muscle fibres that are at least 25% smaller than type 2 fibres, in the absence of other specific pathological features. It is a genetically heterogeneous condition with mutations in ACTA1, RYR1, and TPM3 among the recognised causes. The clinical course is variable, ranging from severe neonatal hypotonia with respiratory failure to mild, non-progressive weakness.
Common clinical features
Neonatal or infantile hypotoniaGeneralised muscle weakness with proximal predominanceRespiratory insufficiency (variable, can be severe in neonates)Feeding difficulties in infancyDelayed motor milestonesJoint contractures and foot deformitiesHigh-arched palate and dysmorphic facial features
From Orphanet’s phenotype annotations (CC BY 4.0). Not a complete list.
Before you apply
Things trial teams commonly ask about for Congenital Fiber Type Disproportion. Not eligibility rules; those are set by each study.
- Muscle biopsy with fibre type analysis (ATPase staining at pH 4.3 and 9.4) confirming the fibre type disproportion pattern is essential; biopsy reports must specify fibre diameter measurements
- Gene panel sequencing covering congenital myopathy genes is required; the specific gene identified (ACTA1, RYR1, TPM3) may determine eligibility for gene-specific sub-studies
- Pulmonary function tests including FVC supine and upright, and sleep study data, are standard eligibility parameters for moderate-to-severe phenotypes
Related conditions
Information, not medical advice. Trial listings are shown as recorded on ClinicalTrials.gov; whether any study is right for you is a decision for you and your clinicians, and eligibility is decided by each research team. Disease information from Orphanet (CC BY 4.0).